Submission #995154

#	Time	Username	Problem	Language	Result	Execution time	Memory
995154		Sokol080808	Star triangles (IZhO11_triangle)	C++17	100 / 100	783 ms	22944 KiB

triangle

#include <bits/stdc++.h>
#include <malloc.h>

using namespace std;

#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

// #ifndef ONPC
//     freopen("triangles.in", "r", stdin);
//     freopen("triangles.out", "w", stdout);
// #endif


    int n;
    cin >> n;
    vector<array<int, 2>> a(n);
    map<int, vector<int>> x, y;
    
    for (int i = 0; i < n; i++) {
        cin >> a[i][0] >> a[i][1];
        y[a[i][0]].push_back(a[i][1]);
        x[a[i][1]].push_back(a[i][0]);
    }

    set<int> ok_x, ok_y;
    for (int i = 0; i < n; i++) {
        if (!ok_x.count(a[i][0])) {
            ok_x.insert(a[i][0]);
            sort(all(y[a[i][0]]));
        }
        if (!ok_y.count(a[i][1])) {
            ok_y.insert(a[i][1]);
            sort(all(x[a[i][1]]));
        }
    }

    ll ans = 0;
    for (int i = 0; i < n; i++) {
        auto [curx, cury] = a[i];
        ll u = y[curx].end() - upper_bound(all(y[curx]), cury);
        ll d = lower_bound(all(y[curx]), cury) - y[curx].begin();
        ll l = lower_bound(all(x[cury]), curx) - x[cury].begin();
        ll r = x[cury].end() - upper_bound(all(x[cury]), curx);
        ans += (u + d) * (l + r);
    }
    cout << ans << '\n';

    return 0;
}

• Subtask 1: 100 / 100